BCC-CSM2-HR: a high-resolution version of the Beijing Climate Center Climate System Model

Abstract. BCC-CSM2-HR is a high-resolution version of the Beijing Climate Center (BCC) System Model (T266 in atmosphere and 1/4? latitude × longitude ocean). Its development on basis medium-resolution BCC-CSM2-MR (T106 1? ocean) which baseline for BCC participation Coupled Intercomparison Project Phase 6 (CMIP6). This study documents model, highlights major improvements representation atmospheric dynamical core physical processes. evaluated historical climate simulations from 1950 to 2014, performed under CMIP6-prescribed forcing, comparison with its previous BCC-CSM2-MR. Observed global warming trends surface air temperature 2014 are well captured by both BCC-CSM2-HR. Present-day basic mean states during period 1995 then at scale, followed an assessment variabilities tropics including tropical cyclones (TCs), El Niño–Southern Oscillation (ENSO), Madden–Julian (MJO), quasi-biennial oscillation (QBO) stratosphere. It shown that represents energy balance can realistically reproduce main patterns wind, precipitation, land temperature, sea (SST). also improves spatial ice associated seasonal variations hemispheres. The bias double intertropical convergence zone (ITCZ), obvious BCC-CSM2-MR, almost disappears TC activity increased resolution enhanced. cycle ENSO, eastward propagative feature convection intensity MJO, downward propagation QBO all better agreement observations than their counterparts Some imperfections are, however, noted BCC-CSM2-HR, such as excessive cloudiness eastern basin Pacific cold SST biases insufficient number North Atlantic.